Strategic Defense Initiative: Sci-Fi or possible?

I honestly have neither the time or the patience to explain what it is, so if you know it do you think it’s possible to be implemented by some realistic time (even though it’s currently put on hold) in the future or is it pure fantasy?

Here’s a good read.

It could be, but only by a country that took defense seriously.

It is something that should be worked upon irregardless of whether or not we can use it in the short term. Also the argument that if it can’t handle a massive strike from the Russian arsenal then it isn’t worth it, is a stupid one. If we could handle only a portion of a strike from a smaller arsenal like North Korea or Iran then the threat of their arsenal is diminished and it creates uncertainty in those states of what they can actually accomplish.